Effect of anterior–posterior and internal–external motion restraint during knee wear simulation on a posterior stabilised knee design

Grupp, Thomas M.; Saleh, Khaled J.; Mihalko, William M.; Hintner, Martin; Fritz, Bernhard; Schilling, Christoph; Schwiesau, Jens; Kaddick, Christian

doi:10.1016/j.jbiomech.2012.10.017

Cited by 18 publications

(10 citation statements)

References 36 publications

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“…Furthermore, our study showed that a tight PCL leads to a higher stress on the inlay and more anterior-posterior movement. These two factors might increase the polyethylene wear in knee prostheses [33,34]. Even collateral ligament stress was diminished with an increasing release of the PCL from certain degree of flexion, which can be explained with less anterior translation of the tibia.…”

Section: Discussionmentioning

confidence: 99%

Posterior cruciate ligament balancing in total knee arthroplasty: a numerical study with a dynamic force controlled knee model

Steinbrück¹,

Woiczinski²,

Weber³

et al. 2014

BioMed Eng OnLine

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BackgroundAdequate soft tissue balancing is a key factor for a successful result after total knee arthroplasty (TKA). Posterior cruciate ligament (PCL) is the primary restraint to posterior translation of the tibia after cruciate retaining TKA and is also responsible for the amount of joint compression. However, it is complex to quantify the amount of ligament release with its effects on load bearing and kinematics in TKA and limited both in vivo and in vitro. The goal of this study was to create a dynamic and deformable finite element model of a full leg and analyze a stepwise release of the PCL regarding knee kinematics, pressure distribution and ligament stresses.MethodsA dynamic finite element model was developed in Ansys V14.0 based on boundary conditions of an existing knee rig. A cruciate retraining knee prosthesis was virtually implanted. Ligament and muscle structures were simulated with modified spring elements. Linear elastic materials were defined for femoral component, inlay and patella cartilage. A restart algorithm was developed and implemented into the finite element simulation to hold the ground reaction force constant by adapting quadriceps force. After simulating the unreleased PCL model, two models were developed and calculated with the same boundary conditions with a 50% and 75% release of the PCL stiffness.ResultsFrom the beginning of the simulation to approximately 35° of flexion, tibia moves posterior related to the femur and with higher flexion anteriorly. Anterior translation of the tibia ranged from 5.8 mm for unreleased PCL to 3.7 mm for 75% PCL release (4.9 mm 50% release).A decrease of maximum von Mises equivalent stress on the inlay was given with PCL release, especially in higher flexion angles from 11.1 MPa for unreleased PCL to 8.9 MPa for 50% release of the PCL and 7.8 MPa for 75% release.ConclusionsOur study showed that dynamic FEM is an effective method for simulation of PCL balancing in knee arthroplasty. A tight PCL led in silico to more anterior tibia translation, a higher collateral ligament and inlay stress, while retropatellar pressure remained unchanged. Surgeons may take these results in vivo into account.

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Section: Discussionmentioning

confidence: 99%

Posterior cruciate ligament balancing in total knee arthroplasty: a numerical study with a dynamic force controlled knee model

Steinbrück¹,

Woiczinski²,

Weber³

et al. 2014

BioMed Eng OnLine

View full text Add to dashboard Cite

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“…These more lax ligament characteristics are comparable to ligament characteristics defined in this study, despite both approaches (ISO and this study) replicating different ligament conditions. However, only limited published data is available for wear testing according to the newly introduced ISO standard [32, 47]. Haider et al [47] reported a high wear rate of 19.88 mg/10 6 cycles for a posterior-stabilized design without reporting the resulting kinematics.…”

Section: Discussionmentioning

confidence: 99%

“…Haider et al [47] reported a high wear rate of 19.88 mg/10 6 cycles for a posterior-stabilized design without reporting the resulting kinematics. Recently, Grupp et al [32] tested the wear behavior of a posterior-stabilized knee design, comparing the old ISO standard to the recently introduced one. A wear rate more than three times higher was reported when comparing the new to the old ISO standard.…”

Section: Discussionmentioning

confidence: 99%

Wear Behavior of an Unstable Knee: Stabilization via Implant Design?

Reinders

Sonntag

Kretzer

2014

BioMed Research International

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Background. Wear-related failures and instabilities are frequent failure mechanisms of total knee replacements. High-conforming designs may provide additional stability for the joint. This study analyzes the effects of a ligamentous insufficiency on the stability and the wear behavior of a high-conforming knee design. Methods. Two simulator wear tests were performed on a high-conforming total knee replacement design. In the first, a ligamentous-stable knee replacement with a sacrificed anterior cruciate ligament was simulated. In the second, a ligamentous-unstable knee with additionally insufficient posterior cruciate ligament and medial collateral ligament was simulated. Wear was determined gravimetrically and wear particles were analyzed. Implant kinematics was recorded during simulation. Results. Significantly higher wear rates (P ≤ 0.001) were observed for the unstable knee (14.58 ± 0.56 mg/106 cycles) compared to the stable knee (7.97 ± 0.87 mg/106 cycles). A higher number of wear particles with only small differences in wear particle characteristics were observed. Under unstable knee conditions, kinematics increased significantly for translations and rotations (P ≤ 0.01). This increase was mainly attributed to higher tibial posterior translation and internal rotations. Conclusion. Higher kinematics under unstable test conditions is a result of insufficient stabilization via implant design. Due to the higher kinematics, increased wear was observed in this study.

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“…The restraint characteristics of the ankle and comparison to TKR show the high relevance of intact ligament structures on the functionality of the joint. Intact ligament structures may not only help to stabilize TAR, but also help to reduce PE wear due to reduced secondary motions of the joint [90].…”

Section: Wear Testmentioning

confidence: 99%